Information gating-the ability to filter out task-irrelevant information-is central to a broad range of cognition. Individuals vary in their ability o gate distracting information, and this difference relates to differences in goal- directed behavior and memory. Recent evidence indicates that one factor that correlates with the ability to gate distractors is individual differences in chronic multitasking behavior with media ('media multitasking'). Relative to individuals who engage less frequently with multiple streams of media in daily life, heavy media multitaskers (HMMs) appear more susceptible to distractors, whether external (from the environment) or internal (from memory). Given the rising prevalence of media multitasking (MM) behavior, it is increasingly important to understand the relationship between MM behavior and neurocognitive function. To this end, we aim to (a) delineate the relationship between MM behavior, filtering ability, and neural function, and (b) examine whether poor information gating gives rise to positive and negative consequences for memory. We will use task-based and resting-state fMRI to test the hypothesis that decreased distractor filtering in HMMs relative to light MMs (LMMs) relates to differential engagement of bottom-up and top-down attention networks, as well as differences in large-scale connectivity within and between these networks. We will examine how distraction affects memory for task-relevant and irrelevant information, and we will relate differences in memory outcomes to differences in neural activation during distraction (using univariate and multivoxel pattern analyses [MVPA]) and during rest (measuring large-scale network coherence). Aim 1 will examine MM-related differences in perceptual filtering and the consequences for memory, testing the hypotheses that (a) MM-related differences in gating irrelevant perceptual information are associated with differential functioning of the dorsal (top-down) and ventral (bottom-up) frontoparietal attention networks, and (b) these differences impact memory encoding of task-relevant and irrelevant information, as expressed by later remembering or forgetting. Aim 2 will examine MM-related differences in mnemonic filtering and the consequences for the ability to generalize knowledge across events, testing the hypothesis that one benefit of failures to gate distracting internal representations may be increased across-event generalization, because reinstatement of 'distracting' memories may support the building of integrated representations of overlapping experiences. In addition to informing neurocognitive theories of attention, memory, and attention-memory interactions, the proposed research has significant mental health relevance as it will provide some of the first evidence bearing on whether and how media multitasking relates to the function of large-scale neural systems of attention and memory. Moreover, by advancing understanding of the relationship between multitasking behavior and attention, the proposed research may prove informative for assessment and intervention in clinical conditions of attention, such as attention deficit hyperactivity disorder (ADHD) and schizophrenia. PUBLIC HEALTH RELEVANCE: The prevalence of media multitasking has markedly increased in recent years, raising public health questions about potential consequences for cognitive and neural function. This innovative research program will provide critical evidence addressing the relationship between media multitasking behavior and the function of neural systems of attention and memory. By addressing this important but under-explored issue, the planned research will also yield new insights into interactions between attention and memory, which may inform strategies for assessment and remediation of attention deficits in clinical populations, such as ADHD and schizophrenia.